well what do you know so far. i dont think there are any people here that are going to give you a step by step guide. this is more a place of learning then a place of telling people how to do damage to there neighbours network. so if you tell us what you know we can try and fill in some of the blanks for you.

the software u can use for this backtrack.. but its for only WI-FI which are WAP protected, for other secure connection its not it use, but remember hacking is an illigal thing which, this is just for knowledge purpose...

Since i use Wi-Fi on my phone i can tell you that make's no sense cracking a Wi-Fi network. I will explain you what can you if you get in a Wi-Fi network bypassing protections.
1 : You can use victims internet connection
2 : IF that Wi-Fi modem has a web page you can change settings like firewall , change/set modem's password , change/disable modem security .
If on that modem are connected 1 computer and the password is changed , user will be out of the internet in 1-2 minutes so after a simple check will notice the changes made on settings.

Do you know that Wi-Fi is legal worldwide ? think why . In france is legal his use inside of a building not outside.
As a last question : Do you really think that worth to crack someone's wifi ?